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    <title>Document</title>
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<body>
    <script>
        var n = parseFloat(Math.random() * 100)
        switch (n) {
            case 100:
            case 99:
            case 98:
            case 97:
            case 96:
            case 95:
            case 94:
            case 93:
            case 92:
            case 91:
            case 90:
                console.log('A')
                break;
            case 89:
            case 88:
            case 87:
            case 86:
            case 85:
            case 84:
            case 83:
            case 82:
            case 81:
            case 80:

                console.log('B')
                break;
            case 79:
            case 78:
            case 77:
            case 76:
            case 75:
            case 74:
            case 73:
            case 72:
            case 71:
            case 70:
                console.log('C')
                break;
            case 69:
            case 68:
            case 67:
            case 66:
            case 65:
            case 64:
            case 63:
            case 62:
            case 61:
            case 60:
                console.log('D')
                break;
            default:
                console.log('E')
        }

    </script>

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